LOWELL — A Lowell man faces assault charges in an attack on his 2-month-old son, who was in critical condition at a Boston hospital Sunday evening, according to authorities.

Christopher Berry, 22, was scheduled to be arraigned in Lowell District Court Monday after being arrested and charged with assault and battery on a child causing substantial bodily injury, according to a statement from the Middlesex district attorney’s office.

Police, firefighters, and paramedics found Berry’s son in an “unresponsive” state at 215 Mammoth Road on Saturday, the statement said.

At the address where authorities said they found the infant, several neighbors said they constantly heard fights in the apartment since Berry moved in about two months ago with the child and a woman who neighbors said they believe is Berry’s girlfriend.

“I hear banging, yelling, and fighting all the time,” said one man who lives in the Mammoth Road apartment building. He declined to give his name.

The infant was taken to Lowell General Hospital, then to Tufts Floating Hospital for Children in Boston. Lowell ­police and State Police are investigating.